According to "how to think like a researcher," a chapter from how to find out anything, one should begin research by asking answerable questions rather than open-ended questions. based on the guidelines in the text, which is an appropriate research question? which state has the most days of nice weather in a year? is a year-round school calendar a better option for students? what is the most difficult thing about taking a trip abroad? what is the average income of a dentist in the united states?

The correct answer is D.

"What is the average income of a dentist in the United States?" is an appropiate question for research because it has only one possible answer. The average income can be calculated and through deep inquiring one can get the correct answer.

On the other hand, the rest of the questions may present different answers according to the person replying.

the maximum speed limit is 55 mph on a two-lane undivided highway and for vehicles towing trailers.

themselves

an intensive pronoun is a pronoun that ends in self or selves, such as himself, herself, themselves, yourself, ourselves. since band members is a third person plural, the correct intensive pronoun would be themselves. if the band was talked about as a collective noun, itself would be the appropriate intensive pronoun. intensive pronouns are used to add emphasis to the noun it's modifying which is why it directly follows it.